Niyazi Bizak, H. Onder Ozbelge, Levent Yilmaz, B. Filiz Senkal (2000), Macromolecular Chemistry and Physics, vol. 201, num. 5, pp. 577-584 describes the synthesis of boron binding gels and its use for water treatment.
U.S. Pat. No. 4,738,878 (Anderson et al.) describes an in situ wood treatment, applied to a wooden railroad tie. The method comprises the injection of a paste-like preparation in one or several unoccupied spike holes that are present in the rail supporting the tie plate, said preparation containing a water soluble fungicide. The preparation, by lodging in cracks and recesses in communication with the spike hole, kills the existing fungus. As time passes, the fungicide follows the existing or subsequently developed moisture paths up to the most remote sites. This treatment does not use any gels to fill the cavities produced by natural wood degradation agents or to fill a cavity intentionally made.
U.S. Pat. No. 5,553,438 (Hsu) mentions that the service life of a wood pole such as a utility pole is increased if the base of the pole comprises slots penetrating deeply in the wood. These slots are formed prior to pressure treatment of the wood with preservative agents and they improve the penetration of the wood preservative agents. After drying, the butt end of the pole is encased in a shell, suitably of polymeric material, that is bonded to the butt end of the pole and provides a barrier to penetration of fungus or insects, and prevents the passage of liquids which might leach the preservative agent from the pole into the surrounding ground.
U.S. Pat. No. 5,582,871 (Silenius et al.) describes a method for preserving wood against undesirable reactions caused by microorganisms. The method also concerns wood preserved against molds, blue-stain fungi and rot fungi. According to the method, the wood being preserved is treated with a substance capable of inhibiting the growth of microorganisms. This substance penetrates into the wood rather deeply than superficially. This substance is a complexing agent, e.g., EDTA, which is capable of binding transition metals contained in the wood. An aqueous EDTA solution is used to impregnate the wood, and when the wood is impregnated, the complexing agent is precipitated from the aqueous phase. The complexing agent can be precipitated by lowering the pH of the wood, or alternatively, altering the temperature of the wood after the impregnation step. According to the method, the complexing agent precipitated into the wood forms a reserve depot. The complexing agent re-dissolving from the depot is capable of binding transition metals entering the wood via rainwater or contamination.
U.S. Pat. No. 4,761,179 (Goettsche et al.) describes a wood preservative based on a water-dilutable formulation of the compound di-(N-cyclohexyldiazoniumdioxy)-copper, a polyamine, a complex-forming carboxylic acid and, if required, a salt having a fungicidal anion which has a pH in the aqueous solution of not less than 7.5 in the conventional concentration for use
U.S. Pat. No. 6,168,870 (Wall) describes a method of impregnating wood with a plastic plug containing a wood preservative agent. A first step involves dehydrating the polymer plastic plug to reduce its naturally occurring moisture content. A second step involves introducing a liquid wood preservative agent into the polymer plastic plug while it is in a dehydrated state by immersing it in the liquid wood preservative agent and boiling the liquid wood preservative agent at temperatures that are less than that required to turn the polymer plastic plug into a molten state. In accordance with the technique of this method, the liquid wood preservative agent is absorbed into the dehydrated polymer plastic plug in place of the naturally occurring moisture content.
U.S. Pat. No. 7,160,606 (Wall et al.) describes a method of treating building materials with boron and boron treated building materials. The method involves introducing boron during manufacture of the building materials in the form of a water soluble copper-borate complex. The copper-borate complex enables a wider range of glues and adhesives to be used, is slower to leach out, and provides enhanced fungicidal properties.
There was thus a need for a new wood treatment process deprived of the drawbacks commonly associated with the known prior art processes, namely the toxicity, the high cost, a time limited protection efficiency due to fast leaching by rain waters, and allowing to substantially improve the service life of the treated wood article, when the latter is subjected to aggressive elements of the environment in which it is used.